Move over, Mulleavys! Brooklyn-based sisters Lizzy and Darlene Okpo—the masterminds behind the line William Okpo—are the latest (and Opening Ceremony-approved) sibling label on the block. Lizzy and Darlene chatted with us about their number-one fan, Solange Knowles, and taking pointers from dear old dad.

The company is named after your father. Can you explain that decision?

Darlene Okpo: We decided to name the line after our dad, who moved to the U.S. from Nigeria. We've always admired his style. We're inspired by him on a daily basis. He's kind of our style consultant.

Does he have any particularly memorable outfits?

Darlene: Oh yes. He has this blue suit that he wears to this day.

Lizzy: It's a weird blue. There's like a violet mixed into it, and he wears it to a T. He's not afraid of color and that's one thing we always thought was so interesting about him. He always said Americans are scared of color. Everyone loves black, everyone loves white. He likes bold, bold color and he wears it well.

William Okpo has all of these famous fans, most notably Solange. How did you get her hooked?

Darlene: She found [our line] at Opening Ceremony. We just became shopping friends. [That turned] into a real friendship. Now we're all really cool, like sisters.

Lizzy: All of our friends are our cheerleaders. They each ask, What can I do to help? How can I get involved? What do I do for the show? They're there to help. Collectively, that's made a difference.

Darlene: What also helps is people love our backstory. They love the fact that we're humble girls—our upbringing and how we started the line. Lizzy went to school at Pace University for entrepreneurship and I went to Lehman College for fashion merchandising and African-American Studies. Humberto [Leon] and Carol [Lim] of Opening Ceremony, that whole crew…they've been gung-ho for us since day one. We showed at their Super Pier venue this past season. We were part of their takeover featuring designers that they like.

What was the inspiration for spring 2014? And I loved the models' ultra-high hairstyles, by the way.

Lizzy: Darlene and I traveled to Jamaica, and I traveled to Senegal this past July and we just noticed a few common things [to both societies.] They were so easygoing; they just had this freedom. Darlene was so intrigued by this barbershop artwork that we kept seeing. Usually you see it in West African countries. Instead of there just being full-length images of people's hairstyles, there will be cartoon illustrations. So we had an artist sketch our own rendition of what we see as the barbershop art and we made that our primary thumbprint for the collection.

Darlene: This was our first time ever doing our own personal print, so it was something that was really dear to our hearts. That was kind of our introduction into the whole print world.

You collaborated with Puma on a sneaker for spring.

Lizzy: Yeah and another one with Brother Vellies, shoes that are being made in South Africa. So we've been dabbling.

And does your dad give a lot of feedback?

Darlene: All the time! Everyday. We love it because he's really involved in the styling aspect. He'll tell us "that's not right" and we're like, "Dad. Can you stop, please? We're never going to be up to par."